Significant g-factor values of a two-electron ground state in quantum dots with spin-orbit coupling

The magnetization of semiconductor quantum dots in the presence of spin-orbit (SO) coupling and interactions is investigated numerically. When the dot is occupied by two electrons we find that a level crossing between the two lowest many-body eigenstates may occur as a function of the spin-orbit coupling strength. This level crossing is accompanied by a nonvanishing magnetization of the ground state. Using first-order perturbation theory as well as exact numerical diagonalization of small clusters, we show that the tendency of interactions to cause Stoner-type instability is enhanced by the SO coupling. The resulting g factor can have a significant value and thus may influence g -factor measurements. Finally we propose an experimental method by which the predicted phenomenon can be observed.